Method Statement for Excavating Additional 3m Deep Trial Pits (2013!08!13)

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 1 of 16

Method Statement for

Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

for

Hin Keng Station & Approach Structures, Contract No. 1102

This document contains confidential information of Penta-Ocean Construction Co., Ltd. and shall not be copied or amended without approval of the Project Manager Rev Issue Date Status Prepared by Reviewed by Reviewed by

Engineer / Construction

Manager QA Engineer Safety Manager

- 13-8-2013 Submission

Tiu Ching Chiu, Thomas

Date: 13-8-2013 Date: Date:

Reviewed by Approved by

Senior Construction

Manager Project Manager

Date: Date:

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 2 of 16

Content Page

1. The Scope of Works ……………………………………………………………… 3

2. Method and Sequences of Construction …………………………….……….… 3

3. Material, Plants and Labour Resources ………………………………………... 5

4. Construction Programme ………………………………………………………… 5

5. Safety and Environmental Mitigation Measures ……………………………..… 5

6. Flood Protection Measures ……………………………………………………… 5

7. Fire Detection and Protection Measures ……………………………………..… 6

8. Contingency Plan ………………………………………………………………… 6

Appendices

Appendix A - Layout Plan of Additional Trial Pits

Appendix B – Shoring Details

Appendix C - Risk Assessment

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 3 of 16

1. The Scope of Works 18 nos additional trial pit of 3m deep along the slope crest shall be excavated to verify the degree of the compaction of existing fill material before commencement of soil replacement works. The excavation will commenced immediately after completion of tree felling. This method statement outlines the procedure for trial pit excavation. The following soil mechanical tests shall be carried out for the sample retrieved from the trial pit;

i) In-situ density test ii) Relative compaction Test

The movement monitoring on tracks and adjacent Operational Railway Facilities shall be conducted concurrently to review any impact caused by the trial pit excavation to these facilities.

2. Method and Sequences of Construction Underground Services location plans made available by the Client/Engineer will be viewed, pits will be located to avoid such services. A Cable Avoidance Tool (CAT) will be used to identify the location of underground services before excavation. Trial pits are dug by hand using a pick and shovel and extend to a depth about 3m depth. The sides of trial pit must be shored. Refer to the Section 1 to 8 shown in drawing no. 1102/W/HIK/SWL/C22/022A, 023A & 024A, the D.G.W.L is about 5-6m below the existing ground, dewatering will not be required.

i) The location of additional trial pits will be set on site. ii) Field utilities detection will be carried out by competent person at each location of

additional trial pits. iii) Each location would be fenced. iv) Trial pits will be excavated vertically from surface down to 1.2m deep. v) Steel sheet piles to timber board will be used for shoring the vertical surface. The steel

channel or timber wailing and steel strut will be installed. vi) The 1

st layer of wailing and strut will be installed about level about 0.5, below ground. And

the horizontal spacing of struts will be not more than 1.2m vii) Pits will be excavated to required depth. The 2

nd and 3

rd wailing and strut will be installed

at 1m interval down to the trial pit. The steel sheet piles will be extended to the bottom of trial pit. A cat-ladder will be used for access.

viii) Excavated material will be temporary stock pile on site for further backfilling. Temporary stockpile area will be at least 3m from the edge of trial pit.

ix) The temporary stockpile area shall be surrounded by sufficient sand bags and fully covered by a sheet of tarpaulin to prevent from surface run-off.

x) Carried out sampling in the pit for in-situ soil density test and relative compaction test as per requirement.

xi) After completion of sampling, the shoring will be removed for backfilling. xii) Backing in layers, well compacted with tamper up to 300mm from surface. Surfaces to be

reinstated as per original

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 4 of 16

Figure 1 – Additional Trial Pits along the Crest of Slope

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 5 of 16

3. Material, Plants and Labour Resources � Min. 2 workers per team. � Steel sheet piles / Timber Boards � Steel Channel Wailing / Timber Wailing � Steel Tube Struts � Tarpaulin and sand bags. � Hand tools � Tamper

4. Construction Programme

Tentative Start: Early September; Tentative Finish: End September

5. Safety and Environmental Mitigation Measures � Safety access shall be provided. The edge of trial pit shall be fenced off. � Temporary shoring system shall be properly designed. ICE shall check and certify the

temporary works design. After completion of shoring system, ICE shall check and certify the construction of temporary works construction before carrying out any soil in-site test.

� Weekly regularly inspection and checking will be carried out by Competent Person. After checking, CP will report in CSSR-Form 4 and display it on site.

� Temporary stockpile shall be fully covered by tarpaulin sheet and surrounded by continuous sand bags.

6. Flood Protection Measures

Each temporary stockpile shall be surrounded by sufficient sand bags and fully covered with tarpaulin to prevent surface run off into the surface drainage.

Figure 2 – Temporary Stockpile shall be fully covered tarpaulin and surrounded by sand bags.

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 6 of 16

Figure 3 – Typical Temporary Shoring and Struts for Trial Pits

7. Fire Detection and Protection Measures � Smoking is prohibited on site � No Hot-works is required for trial pit excavation.

8. Contingency Plan The movement monitoring on tracks and adjacent Operational Railway Facilities shall be conducted concurrently to review any impact caused by the trial pit excavation to these facilities. If the movement due to the trial excavation exceeding the Alert values be observed, the Contractors shall revise his method excavation and enhance the monitoring scheme including real-time monitoring tract. The Contact will resubmit the method statement to the Engineer and Railway Operator for Approval.

~ END ~

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 7 of 16

Appendix A Layout Plan of Additional Trial Pits

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 8 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 9 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 10 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 11 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 12 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 13 of 16

Appendix B Shoring Details

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 14 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 15 of 16

Penta-Ocean Construction Co., Ltd. Ref.: MS/C/002

Shatin to Central Link Contract 1102 –

Hin Keng Station and Approach Structures Revision : - Date: 13-8-2013

Method Statement for Excavating Additional 3m Deep Trial Pits

Along Existing Slope Crest (7SW-D/FR65)

Page: 16 of 16

Appendix C Risk Assessment